Gear unit having a housing

ABSTRACT

A gear unit includes a housing, a trough for guiding oil and reducing losses due to splashing surrounding a circumferential section of a toothing part, particularly a gear wheel, especially in the radial and axial direction. The trough includes at least three parts, e.g., at least one bottom plate and two side walls, the bottom plate being screw-connected to the two side walls. The trough is fastened to the housing and includes an opening, particularly a channel, especially at its lowest surface area, e.g., particularly at the surface area having the greatest radial distance. In particular, during rotational movement of the gear wheel, oil is conveyed from the oil pan of the gear unit through the opening between the trough and gear wheel, especially to a position higher than the level of the oil pan. The bottom plate and the side walls are stamped bent parts.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/034,820, filed on May 5, 2016, which is a national phase of International Application No. PCT/EP2014/002829, filed on Oct. 21, 2014, which claims priority to German Patent Application No. 10 2013 018 711.7, filed on Nov. 8, 2013, each of which is expressly incorporated herein in its entirety by reference thereto.

FIELD OF THE INVENTION

The present invention relates to a gear unit having a housing.

BACKGROUND INFORMATION

It is generally known that a housing of a gear unit has bearing mountings in which the bearings for the shafts of the gear unit are able to be accommodated, and the related forces are dissipated.

SUMMARY

Example embodiments of the present invention provide a gear unit having a housing, which may protect the environment, particularly save resources.

Among features of example embodiments of the present invention with regard to the gear unit having a housing are that a trough for guiding oil and reducing losses due to splashing surrounds a circumferential section of a toothing part, particularly a gear wheel, especially in the radial and axial direction. The trough includes at least three parts, e.g., at least one bottom plate and two side walls, the bottom plate being screw-connected to the two side walls. The trough is fastened to the housing and includes an opening, particularly a channel, especially at its lowest surface area, e.g., particularly at the surface area having the greatest radial distance. During rotational movement of the gear wheel, oil is conveyed from the oil pan of the gear unit through the opening between the trough and gear wheel, especially to a position higher than the level of the oil pan. The bottom plate and the side walls are stamped bent parts.

An advantage in this context is that with the aid of the gear wheel, oil is able to be delivered from the oil pan of the gear unit to a higher-situated location such as a temporary storage or a collecting channel, and thus from there, bearings and meshing gear teeth are able to be lubricated with lubricating oil. In addition, with the aid of the trough that, at least sectionally, correspondingly follows the contour of the gear wheel, therefore the outline of the rotating gear wheel, e.g., the cylindrical spatial area that is contacted by the rotating gear wheel, losses due to splashing are able to be reduced. To that end, the gap between the rotating gear wheel and the trough, especially the bottom plate of the trough, must be made small. The bottom plate is situated, with its surface section facing the gear wheel, at a radial distance that is set apart only slightly from the radial distance of the crowns of the gear teeth of the gear wheel to the axis of the gear wheel. Therefore, the surface section of the bottom plate facing the gear wheel extends substantially in the circumferential direction and in the axial direction, but with the exception of an opening, always has the same radial distance to the axis of the gear wheel, especially to the axis of the shaft to which the gear wheel is joined in rotatably fixed fashion.

The construction of the trough from only three parts forming it, namely, bottom plate and side walls, permits an especially cost-effective production by screw-connecting these parts.

The distance, particularly the distance in the radial direction, between the bottom plate and the crowns of the gear teeth may be constant in the angle-at-circumference area covered by the trough. This is considered advantageous because a small gap is sufficient as distance in order to achieve the pumping action. Losses due to splashing are therefore able to be reduced.

The bottom plate may have tab sections extending in the radial direction, at which the side walls are screw-connected. An advantage in this case is that the tab sections are able to be produced in an easy manner by bending a punching sheet. In addition, the tab section is able to be aligned parallel to the side wall, e.g., perpendicular to the surface section of the bottom plate extending in the circumferential direction and in the axial direction. Therefore, a simple sturdy connection is attainable between the bottom plate and side wall. In the case of a production series of gear units in which gear wheels of different sizes are used, a transmission ratio that is different in each instance is achievable for each gear unit in the production series. Consequently, however, the bottom plate must be secured at a radial distance adjusted in each case, and thus the axially aligned screws of the screw connection between the bottom plate and side wall at different radial distance, accordingly.

One side wall may have a marking, at which a bore hole is able to be placed for leading through a screw of the screw connection. An advantage in this instance is that depending on the transmission ratio of the gear unit or size, especially the crown circle diameter, of the gear wheel, a bore hole is able to be placed at the radial distance indicated differently in each case, and thus the trough is able to be disposed at different radial distance.

The opening, especially the channel, may be bounded by the bottom plate and the two side walls This is considered advantageous because an oil-conveying opening is able to be produced in an inexpensive and uncomplicated manner.

The bottom plate and each side wall may in each instance be formed in one piece, e.g., integrally. This is considered advantageous because each of the three parts is able to be produced as a stamped bent part, e.g., in a very inexpensive and uncomplicated manner. In this context, even the two side walls are able to be similarly implemented.

According to an example embodiment of the present invention, a housing is provided for a gear unit, the housing having a housing top part and a housing bottom part, the housing top part having a frame-like support section on which wall sections are molded. The frame-like support section is formed integrally, e.g., in one piece, with the wall sections, particularly as a casting, especially as a steel casting.

An advantage in this case is that only the support section must contain a lot of material, e.g., also mass, but not the wall sections. Therefore, great forces are able to be transmitted, while saving on material.

The greatest wall thickness of the wall sections may be less than the greatest wall thickness of the support section. An advantage in this instance is that the wall sections are able to be implemented with thin wall thickness, making it possible to realize the housing while saving on material.

The frame-like support section of the housing top part may have a first and a second transverse rib, in particular, the transverse ribs stretching mainly in the horizontal direction, e.g., in particular, being extended further in the horizontal direction than in any direction transverse to it. The frame-like support section includes two first ribs, the two first ribs being set apart from each other and in each case being joined to the first transverse rib, especially at two points set apart from each other, in particular, the first ribs stretching mainly in the vertical direction, e.g., in particular, being extended further in the vertical direction than in any direction transverse to it. The two second ribs are set apart from each other and in each case being joined to the second transverse rib, especially at two points set apart from each other, in particular, the second ribs stretching mainly in the vertical direction, e.g., in particular, being extended further in the vertical direction than in any direction transverse to it. This is considered advantageous because especially high stability is attainable, accompanied by little expenditure for material. The reason is that the frame-like support section has a rectangular shape, in which the rectangle is bent out of the plane of the rectangle at its two opposite sides, so that the bent areas are located substantially in further planes that are perpendicular to the plane, are set apart from each other, and are parallel to each other.

Each first rib and each second rib may have a lifting eye at its end area facing away from the respective transverse rib. This is considered advantageous because the forces introduced into the housing during transport are introduced directly into the frame-like support section, and not into wall sections having thin wall thickness.

A first rib may be joined at its end area to a bar, especially a support bar, that is joined at its other end to the end area of a second rib, the other rib being joined at its end area to a bar, especially a support bar, that in turn is joined at its other end to the end area of the other second rib. In particular, the two bars are disposed in parallel and set apart from each other. This is considered advantageous because high stability is attainable with the aid of the bracings.

A shaft of the gear unit may be supported by a bearing in the housing, a first part of the bearing mounting being located in the housing top part and a second part of the bearing mounting being located in the housing bottom part, the first part of the bearing mounting being implemented as a thickened section, and being joined to that area of the transverse ribs at which the respective rib is also joined. An advantage in so doing is that an additional bracing of the frame-like support section is provided by the thickened areas.

A housing cover may close an opening in housing top part, the opening being surrounded by the frame-shaped support section, particularly with clearance, especially so that the frame-shaped support section does not directly contact the opening, but rather is set apart from the opening. An advantage in this case is that gear-unit parts are able to be inspected through the opening and maintenance work is able to be carried out. At the same time, no lubricating oil flows out from the gear unit either, since the opening is located on the upper side of the housing top part.

Among features with regard to the gear unit are that it is provided with a housing, a shaft of the gear unit being supported by a bearing in the housing, a first part of the bearing mounting being located in the housing top part and a second part of the bearing mounting being located in the housing bottom part, the first part of the bearing mounting being implemented as a thickened section, and being joined to that area of the transverse ribs at which the respective rib is also joined.

This is considered advantageous because high torsional stiffness and high mechanical stability are attainable.

Example embodiments of the present invention are explained in greater detail with reference to the Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an oblique view of a gear-unit housing according to an example embodiment of the present invention for a gear unit in a first viewing direction, the housing including a housing top part 1 and a housing bottom part 2.

FIG. 2 shows an oblique view of the gear-unit housing in another viewing direction.

FIG. 3 shows an oblique view of the gear-unit housing in a third viewing direction.

FIG. 4 shows an oblique view of housing bottom part 2.

FIG. 5 shows an oblique view of housing top part 1.

FIG. 6 shows the frame-like support section of housing top part 1.

As a segment from housing top part 1, FIG. 7 shows a side wall section 3, which is inserted into the frame-like support section.

As a segment from housing bottom part 2, FIG. 8 shows a wall section having a wave structure, e.g., especially a concave-convex wall section.

FIG. 9 shows oil level 90.

FIG. 10 shows a gear wheel 100 of the gear unit that is mounted in rotatably fixed manner on a shaft 101 supported in the gear-unit housing, and is at least partially surrounded by a trough secured to housing bottom part 2.

FIG. 11 shows the trough itself in oblique view, the trough having side walls 102 and a bottom plate 103.

FIG. 12 shows a side wall 102 of the trough.

FIG. 13 shows bottom plate 103 of the trough.

FIG. 14 shows a gear wheel 100 of the gear unit that is mounted in rotatably fixed manner on a shaft 101 supported in the gear-unit housing.

FIG. 15 is a detail view of a gear wheel 100 and bottom plate 103 of trough.

FIG. 16 is a detail view of a gear wheel 106 and bottom plate 103 of trough.

DETAILED DESCRIPTION

As shown in FIG. 1, housing bottom part 2 is disposed below housing top part 1. Thus, housing top part 1 is situated above housing bottom part 2 in the vertical direction.

Housing top part 1 has a frame-like support section, which takes up and conducts the major portion of the forces. The remaining sections of housing top part 1 are formed only for the oil-tight enclosure of the gear-unit interior, e.g., are formed with thinner wall thickness than the support section and join closely to the support section.

Consequently, housing top part 1 as well as housing bottom part 2 are formed in shell-like fashion.

The frame-like support section of housing top part 1 has a first transverse rib 62. It extends mainly in the horizontal direction.

Two first ribs 61 are set apart from each other, and in each case are joined to first transverse rib 61, particularly at two points set apart from each other.

First ribs 61 stretch mainly in the vertical direction, e.g., are extended further in the vertical direction than in any direction transverse to it.

The frame-like support section of housing top part 1 also has a second transverse rib 62. It extends mainly in the horizontal direction.

Two second ribs 61 are set apart from each other, and in each case are joined to second transverse rib 61, particularly at two points set apart from each other.

Second ribs 61 stretch mainly in the vertical direction, e.g., are extended further in the vertical direction than in any direction transverse to it.

Each first rib 61 and each second rib 61 has a lifting eye 63 at its end area facing away from the respective transverse rib. Thus, the gear unit is able to be picked up at the lifting eyes by hooks or cable and is easily transportable. The forces occurring during transport are introduced at lifting eyes 63 into the end areas and thus into the frame-like support section. Consequently, the gear-unit housing becomes only negligibly deformed and remains undamaged.

A first rib 61 is joined at its end area to a bar 60, particularly a support bar, which at its other end is joined to the end area of a second rib 61. In the same manner, the other rib 61 is joined at its end area to a bar 60, particularly a support bar, that in turn is joined at its other end to the end area of the other second rib 61. The two bars 60 are disposed in parallel and set apart from each other.

As described above, wall sections are conformed to the frame-like support section—formed thus of ribs 61, transverse ribs 62 and bars 60—of housing top part 1, so that the shell-like housing top part is able to be formed in one piece, particularly as a casting.

In this connection, the wall sections, especially also two side wall sections 3 and the wall section having a concave-convex wave structure, are thus integrally molded and conformed to the frame-like support section and implemented in one piece.

Bars 60 stretch mainly in the horizontal direction, e.g., are extended further horizontally than in any direction transverse to that.

The frame-like support section is thus realized by an increase in the wall thickness.

In addition, thickened areas are also provided on housing top part 1, which are intended as bearing mounting for at least one part, especially half, of the circumference of an outer ring of a bearing. These arch-like thickened areas adjoining one another are joined to transverse ribs 62, especially in each case in that end area in which respective rib 61 is joined.

The concave-convex wave structure of the wall sections enlarges the surface area, and therefore reduces resistance to the transfer of heat to the ambient air. In this context, an especially sharp depression is provided as depression 5 for a manipulation area for screw connections. In this case, the screws are connecting screws by which housing top part 1 and housing bottom part 2 are screw-connected.

Housing bottom part 2 has a wave structure 6, particularly a concave-convex wall section, which likewise enlarges the surface area, and therefore reduces resistance to the transfer of heat from the gear-unit interior, especially lubricating oil, to the ambient air.

The housing cover is provided to close an opening in housing top part 1, the opening being surrounded by the frame-shaped support section, especially with clearance. That means that the frame-shaped support section does not directly contact the opening, but rather is set apart from the opening.

As shown in FIG. 10, gear wheel 100 is joined in rotatably fixed manner to shaft 101, which is supported in the housing by a bearing. In this context, the bearing is accommodated in a bearing mounting in the housing, a first part of the bearing mounting being located in housing top part 1 and a second part of the bearing mounting being located in housing bottom part 2.

The lower spatial area surrounding gear wheel 100 is enclosed by the trough, the trough having side walls 102 and a bottom plate 103. Thus, it is able to be fabricated from three parts.

Side walls 102 of the trough are secured to bottom plate 103. At its lowest area, bottom plate 103 has a protuberance 130 directed downward. Protuberance 130 is directed radially away from the gear wheel, and is open at its radially outer end area. Thus, lubricating oil of the gear unit gets from the oil pan of the gear unit through protuberance 130 up to gear wheel 100. Laterally, e.g., on both sides in the axial direction, the protuberance is closed by a respective tab section 120 of side walls 102, so that a channel is formed passing through radially to gear wheel 100.

As illustrated in FIG. 12, in each case side walls 102 are punched out as a sheet-metal part, and at their axial outer side, have markings which identify the positions of bore holes to be introduced, particularly as a function of the transmission ratio of the gear unit and/or toothing data of gear wheel 100.

Screws are guided through the bore holes, making a screw connection achievable between bottom plate 103 and respective side wall 102.

Therefore, depending on the size or other toothing data, the bottom plate is able to be positioned at an optimal radial distance from the central axis of the gear wheel.

Bottom plate 103 is likewise produced as a stamped bent part, and has a U-shaped cross-section. In this context, it is bent such that the distance between the toothing, particularly the crowns of the teeth of the toothing of gear wheel 100 located in the same angle at circumference as bottom plate 103, is constant. Thus, a narrow gap is provided between these tooth crowns and bottom plate 103.

Consequently, a pumping action develops during rotational movement of gear wheel 100, since the lubricating oil located in the tooth spaces is moved with greater velocity than the lubricating oil in the channel. In this manner, lubricating oil is thus conveyed through the channel from the oil pan to gear wheel 100 and is then moved along with it.

The trough also reduces the losses due to splashing during movement of gear wheel 100, for the teeth of the toothing of gear wheel 100 dip in the spatial area surrounded by the trough.

With the exception of tab sections 120 and protuberance 130, U-shaped bottom plate 103 is bent circularly in the circumferential direction, so that the distance between the teeth of the toothing of gear wheel 100 and bottom plate 103 is substantially constant in the corresponding angle-at-circumference area.

Tab sections 120 are directed radially to the outside, so that respective side wall 102 is able to be pressed in the axial direction onto bottom plate 103, particularly at its tab sections 120, and screw-connected.

With the aid of the pumping action of gear wheel 100 in interaction with the trough, oil is pumped to a position situated higher than the oil level of the oil pan, and from there is conducted via a temporary storage or directly to the places to be lubricated, such as bearings or engaging gear teeth. Appropriate conduits or pipes are provided for this purpose.

FIG. 14 shows a gear wheel 100 of the gear unit that is mounted in rotatably fixed manner on a shaft 101 supported in the gear-unit housing. FIG. 15 is a detail view of a gear wheel 100 and bottom plate 103 of trough, and FIG. 16 is a further detail view of a gear wheel 106 and bottom plate 103 of trough.

Protuberance 130 is able to be produced by bending out from the original form of bottom plate 103. To that end, a punching sheet is bent such that two areas, bent in the shape of circle segments, are set apart from each other over an area bent substantially in the shape of a rectangle. After that, the areas bent in the shape of circle segments are pressed against each other, and thus form the circular area of bottom plate 103. At the same time, the areas bent in the shape of circle segments encompass an opening. The area bent in the shape of a rectangle likewise has a centrally located opening and thus forms protuberance 130.

LIST OF REFERENCE NUMERALS

-   1 housing top part -   2 housing bottom part -   3 side wall section -   4 housing cover -   5 depression for manipulation area for screw connections -   6 wave structure, especially concave-convex wall section -   60 bar -   61 rib -   62 transverse rib -   63 lifting eyes -   90 oil level -   100 gear wheel -   101 shaft -   102 side wall -   103 bottom plate -   120 tab section -   130 protuberance 

What is claimed is:
 1. A gear unit, comprising: a housing; and a trough adapted to guide oil and reduce losses due to splashing surrounding a circumferential section of a toothing part and/or a gear wheel, in radial and axial directions, the trough including at least three parts, including at least one bottom plate and two side walls, the bottom plate being screw-connected to the two side walls, the trough being fastened to the housing, the trough having an opening and/or a channel, at a bottom surface area and/or at a surface area having a greatest radial distance from a rotational axis of the toothing part and/or gear wheel, during rotational movement of the toothing part and/or the gear wheel, oil being conveyed from an oil pan of the gear unit through the opening and/or the channel between the trough and the toothing and/or the gear wheel, to a position higher than a level of the oil pan; wherein a radial distance between the bottom plate and crowns of gear teeth of the gear unit is constant in a circumferential area covered by the trough.
 2. The gear unit according to claim 1, wherein the bottom plate and the side walls being stamped bent parts.
 3. The gear unit according to claim 1, wherein the bottom plate includes tab sections extending in the radial direction, at which the side walls are screw-connected.
 4. The gear unit according to claim 1, wherein one side wall includes a marking at which a bore hole is able to be placed for leading through a screw of a screw connection.
 5. The gear unit according to claim 1, wherein the opening and/or the channel is bounded by the bottom plate and the two side walls.
 6. The gear unit according to claim 1, wherein the bottom plate and each side wall are each formed in one piece.
 7. The gear unit according to claim 1, wherein the housing includes a housing top part and a housing bottom part, the housing top part having a support section on which wall sections are molded, the support section being formed integrally with the wall sections, as a casting and/or a steel casting.
 8. The gear unit according to claim 7, wherein a greatest wall thickness of the wall sections is less than a greatest wall thickness of the support section.
 9. The gear unit according to claim 7, wherein the support section of the housing top part includes a first and a second transverse rib and the support section includes two first ribs, the two first ribs being set apart from each other and in each case being joined to the first transverse rib at two points set apart from each other, the two second ribs being set apart from each other and in each case being joined to the second transverse rib at two points set apart from each other.
 10. The gear unit according to claim 9, wherein the transverse ribs extend substantially in a horizontal direction and/or extend further in the horizontal direction than in any direction transverse to the horizontal direction.
 11. The gear unit according to claim 9, wherein the first ribs extend substantially in a vertical direction and/or extend further in the vertical direction than in any direction transverse to the vertical direction.
 12. The gear unit according to claim 9, wherein the second ribs extend substantially in the vertical direction and/or extend further in the vertical direction than in any direction transverse to the vertical direction.
 13. The gear unit according to claim 9, wherein each first rib and each second rib includes a lifting eye at an end area facing away from a respective transverse rib.
 14. The gear unit according to claim 9, wherein a first one of the first ribs is joined at an end area to a bar and/or a support bar, which is joined at another end to an end area of a first one of the second ribs, a second one of the first ribs being joined at an end area to a bar and/or a support bar that is joined at another end to an end area of a second of the second ribs.
 15. The gear unit according to claim 14, wherein the bars are disposed in parallel and set apart from each other.
 16. The gear unit according to claim 1, wherein a housing cover closes an opening in the housing top part, the opening in the housing top part being surrounded by a support section, with clearance, so that the support section does not directly contact the opening in the housing top part, but is set apart from the opening in the housing top part.
 17. The gear unit according to claim 9, wherein a shaft of the gear unit is supported by a bearing in the housing, a first part of the bearing mounting being located in a housing top part and a second part of the bearing mounting being located in a housing bottom part, the first part of the bearing mounting including a thickened section, and being joined to an area of the transverse ribs at which the respective rib is also joined. 